What is the purpose of small bowel enteroscopy in a patient with a suspected small bowel disorder?

Purpose of Small Bowel Enteroscopy

Small bowel enteroscopy serves to directly visualize, biopsy, and therapeutically intervene throughout the entire small intestine when non-invasive imaging and standard endoscopy have failed to establish a diagnosis or when tissue sampling and endoscopic treatment are specifically required. 1

Primary Clinical Indications

Small bowel enteroscopy (balloon-assisted or single-balloon) is indicated for:

• Tissue diagnosis when capsule endoscopy or cross-sectional imaging identifies lesions requiring histologic confirmation 2
• Therapeutic intervention including stricture dilation, polypectomy, hemostasis of bleeding lesions, and management of angiodysplasia 3, 4
• Retrieval of retained capsules following capsule endoscopy 2
• Direct visualization when other modalities are inconclusive despite high clinical suspicion for small bowel pathology 1

Diagnostic Yield by Clinical Presentation

The diagnostic performance varies significantly based on presenting symptoms:

• Abdominal pain: 78.6% diagnostic yield 3
• Occult GI bleeding: 52.4% diagnostic yield 3
• Overt GI bleeding: 42.9% diagnostic yield 3
• Abnormal imaging findings: 50.0% diagnostic yield requiring tissue confirmation 3
• Overall positive findings: 65.5-80% across all indications 3, 4

Position in Diagnostic Algorithm

Enteroscopy is NOT a first-line test. 1 It should be performed only after:

1. Standard ileocolonoscopy and esophagogastroduodenoscopy have been completed 1
2. Capsule endoscopy or cross-sectional imaging (MR/CT enterography) have been performed and either:
   • Identified lesions requiring biopsy or treatment 2
   • Remained negative despite persistent symptoms and elevated inflammatory markers 1

For suspected Crohn's disease specifically: Enteroscopy is reserved for situations where ileocolonoscopy and MR/CT enterography are negative or inconclusive, yet it remains imperative to determine if active small bowel disease is present 1

Therapeutic Capabilities

Enteroscopy enables same-session treatment comparable to standard endoscopy 4:

• Hemostasis: Argon plasma coagulation or injection therapy for bleeding lesions (therapeutic yield 14.6%) 3
• Stricture dilation: Management of Crohn's strictures, though perforation risk increases to 1.74% with therapeutic intervention versus 0.12% without 1
• Polypectomy and tumor resection: Removal of small bowel polyps in polyposis syndromes 4
• Biopsy sampling: Tissue diagnosis throughout the entire small intestine 5

Technical Performance

Modern single-balloon and double-balloon systems achieve:

• Depth of insertion: 240 ± 100 cm via oral route; 140 ± 90 cm via anal route 4
• Area of interest reached: 80.7% of cases 3
• Complete small bowel visualization: Possible in 25% when total enteroscopy attempted using both oral and anal approaches 5
• Procedure time: 62-73 minutes average 5, 4

Safety Profile and Complications

Enteroscopy carries higher risks than standard endoscopy, particularly with therapeutic intervention: 1

• Perforation: 0.12% (diagnostic only) vs. 1.74% (with therapeutic intervention, primarily after stricture dilation) 1
• Bleeding: 2.5% overall, with majority occurring after polypectomy 1
• Technical failure rate: 5.5% 3
• Minor complications: 11.7% 3

Critical Clinical Impact

Enteroscopy findings alter management in 75-76% of patients 1, 3:

• Endoscopic therapy: 41.5% of patients 4
• Medical treatment modification: 17% 4
• Surgical intervention: 17.5% 4

Key Pitfalls to Avoid

• Do not use enteroscopy as a first-line investigation for chronic diarrhea or abdominal pain without prior standard endoscopy and imaging 1, 6
• Do not perform enteroscopy in known Crohn's disease with strictures without prior cross-sectional imaging to assess retention risk 2
• Do not substitute enteroscopy for capsule endoscopy when mucosal visualization alone is needed without therapeutic intent 1
• Recognize that enteroscopy requires sedation, is time-consuming, and carries procedural risks that must be justified by diagnostic uncertainty or therapeutic necessity 1, 5